The present invention relates to a re-sealable container including a closure which may be releasably secured in a closed position.
In the packaging industry, it is customary to distribute particulate materials such as dog food, cat food, flour, cereal, fertilizer, cement, and other dry products in a bag, box or other container. Conventional containers, particularly bags, include a front wall, a back wall and side walls, each of the walls having upper and lower ends. Normally, the lower ends of the wall members are folded to form a flap to close the lower end of the bag. The upper end of the bag is closed by folding the upper ends of the wall members downward to create a flap which is glued to the front wall member.
To pour contents from a conventional bag, a user tears a corner of the bag so that the contents may be dispensed or poured through the corner. With the corner torn, however, it is difficult to re-seal or re-close the bag.
One solution to this problem is described in U.S. Pat. No. 6,048,100 to Thrall, which discloses a bag including an upper flap permanently adhered to the front wall of the bag, except for a flap portion near one of the side walls. The flap portion includes a strip of non-stick release liner adhered to it. Strips of exposed adhesive are secured to the front wall of the bag. When the flap is folded over the exposed adhesive, the liner sticks to the adhesive and seals the bag closed along the flap portion. Because of the non-stick material, the closure is movable between a non-sealed open position and a sealed closed position.
Although the Thrall closure facilitates a bag re-sealing, it suffers shortcomings. First, the release liner and exposed adhesive frequently become contaminated with the contents of the bag as those contents are poured. Accordingly, the ability of the closure to remain closed diminishes with use. Second, because the flap portion of the closure is easily pulled from the release liner, it is difficult to detect tampering of the bag.
Another, unrelated closure system is disclosed in U.S. Pat. No. 4,824,261 to Provost. Provost discloses a pair of strips of a hook-and-loop fastening system, identified by the trademark VELCRO. One strip from the pair is hot glued across the width of the front wall of a bag. A second strip is hot glued across a closure flap, to an underside which faces the front wall. A portion of the closure flap that extends beyond the second strip is hot glued to the front wall. A piece of cording is glued to the front wall of the bag under the closure flap. The cording is used to fracture the closure flap and act as a tamper-proof closing for the bag, prior to initial opening.
The tamper-proof re-sealable system of Provost suffers shortcomings as well. First, the velcro strips extend across the width of the bag. Thus, when the strips are pulled apart along a corner, and contents are poured from that corner, the strips tend to separate across the entire width of the bag. This causes excess contents to spill from the bag. Additionally, each of the components of the closure system are individually hot-melt glued to the front wall and flap, which results in increased production costs.
The aforementioned problems are overcome in the present invention wherein a tamper-proof, re-sealable container closure label includes a hook-and-loop fastener system and a tamper-proof tear strip.
In a first embodiment, a re-sealable container closure label, also referred to herein as a re-sealable bag closure label (xe2x80x9cRBCLxe2x80x9d), includes a base ply having pressure sensitive adhesive applied to its underside. A pair of strips of hook-and-loop fastening system is adhered to the top side of the base ply. A tear strip also may be adhered to the top of the base ply. Further, a cover ply is adhered over the base ply, sandwiching the pair of strips of a hook-and-loop fastening system and the tear strip between the cover ply and the base ply. Optionally, the tear strip may be replaced with a set of perforations or tear lines in the cover ply adjacent the hook-and-loop fastening system.
In a second embodiment, the RBCL includes a base ply having a pressure-sensitive adhesive applied to its underside. A pair of strips of a hook-and-loop fastening system is adhered over the top side of the base ply. A tear strip, string, cord, tape, or the like is adhered to the top of the base ply. Further, the base ply or tear strip may include a tab so that the tear strip may be easily grasped by a user.
In a preferred process of applying the RBCL to a conventional bag, the RBCL is first secured to a front wall of a bag before a closure flap of the bag is closed and sealed against the front wall. Preferably, the RBCL is adhered to a corner of the bag, near an upper end of the front wall. The RBCL may also extend across the width or other portion of the bag if desired. As will be appreciated, the RBCL of the present invention may also be applied to and used with other conventional containers, for example, boxes, in a similar manner. An adhesive, such as a hot-melt glue, is applied over the front wall of the bag and the RBCL, preferably over the area coinciding with the tear strip and the hook-and-loop system of the RBCL. The closure flap is folded over and against the hot-melt glue, thereby sealing and closing the bag over the front wall and the RBCL. When the closure flap is hot-melt glued over the first embodiment RBCL the flap preferably overlays both the strips of hook-and-loop fastening system and the optional tear strip. But when the closure flap is hot-melt glued over the second embodiment RBCL, the flap adheres to the second ply, overlapping the hook-and-loop fastening strips, but not the tear strip or set of perforations.
To open a bag or box including the RBCL, a user grasps and pulls the tear strip of the RBCL. With regard to the first embodiment explained above, this action fractures the closure flap to make an opening flap. With regard to the second embodiment explained above, this action only tears the second ply of the RBCL to make an opening flap. The opening flaps of either embodiment may then be pulled away from the front wall to separate the strips of the hook-and-loop fastening system thereby opening the container. A user may close and re-seal the container by closing the opening flap and pressing together the strips back into releasable attachment with one another.
The RBCL of the present invention provides a tamper-proof, re-sealable and re-closable container closure system with many benefits. First, the closure system is self-contained, that is, multiple individual parts need not be individually hot-melt glued to a container. Second, the hook-and-loop fastening system is reliable and not easily contaminated when contents are poured from the bag. Finally, with regard to the second embodiment including a cover ply over the hook-and-loop system, the possibility of contaminating the hook-and-loop system with hot-melt glue as the RBCL is applied to a container is greatly diminished, thereby reducing the number of defective, difficult-to-open closure systems.
These and other objects, advantages and features of the invention will be more readily understood and appreciated by reference to the detailed description of the preferred embodiments and the drawings.